Multicolor ink jet printing method

ABSTRACT

A method for the coloration of a substrate comprising ink jet printing a first and second set of inks onto the substrate wherein: 
     (a) the first set of inks consists of one or more inks each of which independently contains a colorant selected from yellow, magenta, cyan and optionally black; and 
     (b) the second set of inks comprises one or more inks each of which independently contains a dye selected from: 
     a yellow dye of Formula (1) or salt thereof, an orange dye of Formula (2) or salt thereof, 
     a red dye of Formula (3) or salt thereof and a blue dye of Formula (4) or salt thereof, 
     wherein Formulae (1) to (4) are as defined in the description. 
     Also claimed is a set of inks, ink jet printer cartridges, an ink jet printer and substrates printed using the printing method.

The present invention relates to a colour ink jet printing method, to aset of inks, to ink jet printer cartridges, to substrates printed usingthe method and to an ink jet printer.

Ink jet printing is a non-impact printing technique which involvesejecting, thermally or by action of an oscillating piezo crystal,droplets of ink from one or more fine nozzles directly onto a substrate.The ink may be aqueous, solvent or hot melt based.

The printing of textiles is conventionally carried out by screen orroller printing using gravure engraved cylinders. The design to beprinted has to be engraved on to a cylinder and each individual colourin a design requires the application of a separate screen with a colourpremixed to the required shade. This is a long and slow process and itcan take many months for a textile design to appear as a printedtextile. Consequently, there is a demand for a printing process whichenables new designs to be printed onto a textile quickly for proofingpurposes and for small production runs.

Ink jet printing of textiles offers the potential to transfer a designto a textile much faster than traditional textile printing methods.However, conventional colour ink jet printers operate with a colouringsystem which uses three subtractive primary colours (Cyan, Magenta andYellow) together with black, hereinafter referred to as CMYK. Thiscolouring system only provides a limited range of colours compared withconventional textile printing methods.

The limited colour range provided by conventional colour ink jetprinters also limits their applicability in other imaging technologies,particularly where high resolution images are required from digitalcameras or when printing images from the Internet. These“photorealistic” applications require a wide range of colours to produceimages of the same photographic quality as those prepared byconventional screen printing methods.

We have surprisingly found that the colour gamut of an ink jet printeris extended close to that obtained using conventional printing methodswhen a combination of inks containing dyes with specific calorimetricpositions in colour space are used together with a CMYK colouring systemin an ink jet printer.

According to a first aspect of the present invention there is provided amethod for the coloration of a substrate comprising ink jet printing afirst and second set of inks onto the substrate wherein:

(a) the first set of inks consists of one or more inks each of whichindependently contains a colorant selected from yellow, magenta, cyanand optionally black; and

(b) the second set of inks comprises one or more inks each of whichindependently contains a dye selected from:

a yellow dye of Formula (1) or salt thereof:

wherein:

X is a labile group or atom;

R¹ is alkyl or —NH₂;

A is —NR²R³, —OR² or halogen;

R² is H or optionally substituted alkyl; and

R³ is optionally substituted phenyl;

an orange dye of Formula (2) or salt thereof:

wherein:

R⁴ is H or optionally substituted alkyl;

X is as hereinbefore defined;

B is —NR⁵R⁶, —OR⁵ or halogen; and

R⁵ and R⁶ independently are H or optionally substituted alkyl;

a red dye of Formula (3) or salt thereof:

wherein:

X is as hereinbefore defined;

E is —NR⁷R⁸, —OR⁷ or halogen;

each R⁷ is independently H or alkyl; and

R⁸ is optionally substituted aryl;

and a blue dye of Formula (4) or salt thereof:

wherein:

each X independently is as hereinbefore defined;

each L independently is an optionally substituted alkylene group;

each W independently is halogen or a group of the formula —OR⁹ or—NR¹⁰R¹¹;

R⁹ is H or alkyl, R¹⁰ is H or optionally substituted alkyl; and

R¹¹ is an optionally substituted aryl group.

FIG. 1 compares the colour gamut obtained using a first set of inksalone (i.e. cyan, magenta and yellow) with that obtained using a firstand second set of inks according to the present invention. In FIG. 1 thedots indicate the colour gamut from the first and second sets of inks.The crosses show the colour gamut from the first set of inks alone.

The coloration method of the present invention achieves a wide colourgamut by applying, in any combination, the inks from the hereinbeforedefined first and second sets of inks to a substrate using an ink jetprinter.

Preferably, the first set of inks consists of yellow, magenta and cyaninks and preferably also a black ink. Accordingly, in a preferredembodiment, the first set of inks consists of an ink containing a yellowcolorant, an ink containing a magenta colorant, an ink containing a cyancolorant and an ink containing a black colorant.

The second set of inks comprises from one to four, preferably two tofour and especially four inks each of which independently contains a dyeselected from the hereinbefore defined dyes of the Formulae (1) to (4).

In a preferred embodiment, the second set of inks comprises an inkcontaining a dye of Formula (1), an ink containing a dye of Formula (2)an ink containing a dye of Formula (3) and an ink containing a dye ofFormula (4).

In view of the above preferences, in an especially preferred embodimentof the present invention the first set of inks consists of an inkcontaining a yellow colorant, an ink containing a magenta colorant, anink containing a cyan colorant and an ink containing a black colorant;and the second set of inks comprises an ink containing a dye of Formula(1), an ink containing a dye of Formula (2) an ink containing a dye ofFormula (3) and an ink containing a dye of Formula (4).

As will be understood, the ink of the first set of inks which containsthe yellow colorant is a different shade of yellow to that of the ink ofthe second set of inks which contains the yellow dye of Formula (1) soas to maximise the colour gamut available to the ink jet printer.

It is preferred that each of the inks in the first and second set ofinks are a different colour.

The inks may be applied to the substrate in any combination, providedthat at least one ink from each of the two sets is applied. Theparticular combination of inks selected from the first and second setsof inks will be chosen to achieve a desired colour at a specificposition on the substrate. Therefore, a single ink from the first orsecond set of inks or any combination of inks from the first and secondsets may be applied to a particular point on a substrate to achieve aspecific colour at that point. By way of illustration, if a redcorresponding to the colour of the red ink of the second set of inks wasrequired at a particular point on the substrate, then that ink alonewould be applied to that part of the substrate by the ink jet printer.

In the dyes of Formula (1), it is preferred that:

R¹ is C₁₋₄-alkyl or —NH₂, more preferably methyl, ethyl or —NH₂ andespecially —NH₂;

R² is H or optionally substituted C₁₋₆-alkyl, more preferably H orC₁₋₄-alkyl and especially H, methyl and ethyl;

R³ is phenyl substituted by —COOH ,—SO₃H or —OH, more preferably phenylsubstituted by —SO₃H; and

the group A is a group of the formula —NR²R³, —OR² or Cl, morepreferably —NR²R³.

The dyes of Formula (1) may be prepared by methods analogous to thosedescribed in the art for other similar azo dyes, for example asdescribed in EP 559 331A1, page 5, wherein the compound of formula (4)has the formula H-A.

In the dyes of Formula (2), it is preferred that:

R⁴ is H or optionally substituted C₁₋₄-alkyl, more preferably H, methylor ethyl and especially methyl;

R⁵ and R⁶ are preferably each independently H or C₁₋₄-alkyl, morepreferably H; and

B is preferably —NR⁵R⁶, —OR⁶ or Cl, more preferably —NR⁵R⁶ andespecially —NHR⁶.

The dyes of Formula (2) may be prepared by methods analogous to thosedescribed in the art for similar azo dyes, for example as described inGB 859,990, Example 1.

Preferred dyes of Formula (3) are those in which:

R⁷ is H or C₁₋₄-alkyl, more preferably H, methyl or ethyl and especiallyH;

R⁸ is optionally substituted phenyl or naphthyl and especially phenyloptionally substituted by C₁₋₄-alkyl; and

E is —NR⁷R⁸, —OR⁷ or Cl, more preferably —NR⁷R⁸ and especially —NHR⁸.

The dyes of Formula (3) may be prepared by methods analogous to thosedescribed in the art for other similar azo dyes, for example asdescribed in GB 834,304, Example 3.

Preferred dyes of the Formula (4) are those in which:

R⁹ is H or C₁₋₄-alkyl, especially H;

R¹⁰ is H or optionally substituted C₁₋₆-alkyl, more preferably H orC₁₋₄-alkyl and especially H or methyl;

R¹¹ is an optionally substituted phenyl, more preferably phenylsubstituted with carboxy, hydroxy or sulpho and especially phenylsubstituted with one or preferably two sulpho groups;

each L independently is an optionally substituted C₁₋₆-alkylene group,more preferably a C₁₋₆-alkylene group and especially an alkylene groupof the formula —C_(m)H_(2m)—,

wherein m is an integer from 1 to 6, preferably 2 or 3; and each Windependently is —OR⁹, —NR¹⁰R¹¹ or Cl, more preferably —NR¹⁰OR¹¹ andespecially —NHR¹¹.

The dyes of Formula (4) may be prepared by methods analogous to thosedescribed in the prior art for similar triphenodioxazine dyes, forexample as described in EP 576 123 Al on pages 6 to 8 and Example 1.

The cyan, yellow, magenta and black colorants present in the inks of thefirst set of inks may be selected from any of the colorants suitable foruse in ink jet printers utilising the conventional CMYK colouring systemfor example, cyan, yellow, magenta and black pigments and dyes.Preferably the colorants present in the first set of inks are dyes, morepreferably dyes which contain fibre reactive groups.

When any of the first set of inks contain a fibre reactive dye, any ofthe cyan, magenta, yellow and black reactive dyes listed in the ColourIndex are suitable. Preferred reactive dyes comprise of one or morechromophores and one or more fibre reactive groups. Preferred fibrereactive groups are cellulose reactive groups, more preferably,vinylsulphone, sulphatoethylsulphone, halopyrimidine and holotriazinegroups. Preferred halotriazine groups are fluoro and chlorotriazinegroups, more preferably mono-chlorotriazine groups. Examples of suitablechromophores include azo, phthalocyanine, triphenodioxazine,anthraquinone and formazan chromophores. Especially preferred reactivedyes suitable for use in the first set of inks comprise one or more azo,phthalocyanine, triphenodioxazine, anthraquinone and formazanchromophore and one or more mono-chlorotriazine group. It is preferredthat the reactive dye is water soluble.

Specific examples of reactive dyes suitable for use as colorants in thefirst set of inks include for example. Colour Index (C.I.) Reactive Red31, C.I. Reactive Blue 71 and C.I. Reactive Black 8. These dyes areavailable from Zeneca Ltd.

In a preferred embodiment, the cyan colorant in the first set of inks isa dye of the Formula (5), or salt thereof

wherein:

Pc is a phthalocyanine nucleus;

Z is —NR¹²R¹³, —OR¹³ or halogen; wherein

R¹² is H or optionally substituted alkyl;

R¹³ is H, optionally substituted alkyl or optionally substituted aryl;

X is as hereinbefore defined;

a is 1 to 3;

b is 1 to 3; and

(a+b)=4.

It is preferred that R¹² is H or optionally substituted C₁₋₄-alkyl, morepreferably H or C₁₋₄-alkyl and especially H.

Preferably R¹³ is H, optionally substituted C₁₋₆-alkyl or optionallysubstituted phenyl, more preferably H or optionally substitutedC₁₋₄-alkyl and especially methyl or ethyl.

When Z is halogen it is preferably chloro.

Preferably Z is a group of the formula —NR¹²R¹³ or —OR¹³, morepreferably —NHR¹³ or —OR¹³ and especially methoxy and ethoxy.

The dyes of Formula (5) may be prepared by methods analogous to thosedescribed in the art for similar phthalocyanine compounds. For example asuitable method is described in GB 805,562, Example 12.

In a preferred embodiment the yellow colorant present in the first setof inks is a dye of Formula (6) or salt thereof:

wherein:

Y is a halogen or a group of the formula —NR¹⁵R¹⁶ or —OR¹⁶, wherein R¹⁵is H or optionally substituted C₁₋₄-alkyl, and R¹⁶ is H optionallysubstituted alkyl or aryl;

R¹⁴ is H, optionally substituted alkyl or aryl; and

each X independently is as hereinbefore defined.

Preferably R¹⁴ is H or optionally substituted C₁₋₄-alkyl, morepreferably C₁₋₄-alkyl and especially methyl or ethyl.

Preferably R¹⁵ is H or C₁₋₄-alkyl, more preferably H, methyl or ethyland especially H.

Preferably R¹⁶ is H, optionally substituted C₁₋₄-alkyl or optionallysubstituted phenyl, more preferably H, C₁₋₄-alkyl or phenyl andespecially H, methyl and ethyl.

When Y is halogen it is preferably chloro.

It is preferred that Y is a group of the formula —NR¹⁵R¹⁶, morepreferably —NHR¹⁶ and especially —NH₂.

The dyes of Formula (6) may be prepared by methods analogous to thosedescribed in the art for similar azo dyes. For example a suitable methodis described in GB 1,271,226, Examples 2 to 153.

In a preferred embodiment, the magenta colorant present in the first setof inks is a dye of the formula (7) or salt thereof:

wherein:

G is halogen or a group of the formula —NR¹⁷R¹⁸ or —OR¹⁷, wherein R¹⁷ isH or optionally substituted alkyl;

R¹⁸ is H, optionally substituted aryl or optionally substituted alkyl;

R¹⁹ and R²⁰ are each independently C₁₋₄-alkyl; and

X is as hereinbefore defined.

It is preferred that R¹⁷ is H or optionally substituted C₁₋₄-alkyl, morepreferably H or C₁₋₄-alkyl and especially H or methyl.

Preferably R¹⁸ is H, optionally substituted phenyl or optionallysubstituted C₁₋₆-alkyl, more preferably H, C₁₋₆-alkyl or phenylsubstituted by C₁₋₄-alkyl, —COOH or —SO₃H, especially C₁₋₆-alkyl andphenyl substituted by methyl, ethyl or —SO₃H and more especially phenylsubstituted with —SO₃H and methyl.

R¹⁹ and R²⁰ are preferably independently methyl, ethyl or iso-propyl.

When G is halogen it is preferably chloro.

Preferably G is a group of the formula —NR¹⁷R¹⁸, more preferably —NHR¹⁸.

The dyes of Formula (7) may be prepared using methods analogous to thosedescribed in the art for other azo dyes. For example a suitable methodis described in W094/22961.

A preferred black colorant present in the first set of inks is a 1:2Chromium or Cobalt complex, or mixture thereof, of Formula (8) or saltthereof:

wherein:

T is halogen or a group of the formula —NR²¹R²² or —OR²¹, wherein

R²¹ is H or optionally substituted alkyl or optionally substituted aryl;

R²² is H or optionally substituted alkyl;

M is Cr or Co; and

X is as hereinbefore defined.

Preferably R²¹ is H, optionally substituted C₁₋₆-alkyl or optionallysubstituted phenyl, more preferably H or C₁₋₄-alkyl and especially H,methyl or ethyl.

Preferably R²² is H or C₁₋₄-alkyl, more preferably H.

When T is halogen it is preferably chloro.

It is preferred that T is a group of the formula —NR²¹R²², morepreferably —NHR²¹.

Preferably a mixture of Cobalt and Chromium complexes of the dyes ofFormula (8) are present in the black ink. Preferred mixtures comprisethe components:

(a) from 50 to 95, more preferably from 55 to 80 and especially from 60to 75 parts of the 1:2 chromium complex; and

(b) from 5 to 50, more preferably 20 to 45 and especially 40 to 25 partsof the 1:2 cobalt complex, wherein all parts are by weight and the parts(a)+(b)=100.

The dye of Formula (8) and the complexes thereof may be prepared usingmethods analogous to those described in the art for similar azo dyes.For example, a suitable method is disclosed in GB 985,481, Examples 1and 2.

A further preferred black colorant suitable for use in the first set ofinks is a dye of the Formula (9) or a salt thereof.

wherein:

X is as hereinbefore defined; and

R²³ and R²⁴ are each independently H or optionally substituted alkyl.

Preferably R²³ and R²⁴ are each independently H or C₁₋₆-alkyl optionallysubstituted by —OH or SO₃H, more preferably H or C₁₋₄-alkyl andespecially H.

The sulpho group on the phenyl ring is preferably attached at the paraposition relative the second sulpho group on the ring.

It is preferred that the dye of Formula (9) is mixed with a smallquantity of a yellow and/or a red dye to give a neutral black shade.

A preferred mixture of dye comprises:

(a) from 50 to 95, more preferably from 60 to 80 parts of the dye ofFormula (9);

(b) from 5 to 20, more preferably from 5 to 15 parts of a yellow dye;and

(c) from 10 to 30, more preferably from 15 to 25 parts of a red dye;

wherein all parts are by weight and the sum of the parts (a), (b) and(c)=100. The red and yellow dyes which may be present in the mixture arepreferably azo dyes, more preferably water-soluble azo dyes.

A preferred red dye is the dye of the hereinbefore defined Formula (3)wherein X is Cl and E is 2-methylphenylamino. A preferred yellow dye isthe dye of the hereinbefore defined Formula (1) wherein X is Cl, A is3-sulpho-N-methylaniline or 4-sulpho-N-methyl anilino and R¹ is amino.

An especially preferred yellow dye is a 1:1 mixture of the dyescomprising:

(i) a dye of Formula (1) in which X is Cl, A is 3-sulpho-N-methylanilinoand R¹ is amino; and

(ii) a dye of Formula (1) in which X is Cl, A is4-sulpho-N-methylanilino and R¹ is amino.

In view of the foregoing preferences an especially preferred blackcolorant comprises:

(a) from 60 to 80 parts of the dye of Formula (10);

(b) from 15 to 25 parts of a 1:1 mixture of dyes of Formula (11); and

(c) from 5 to 15 parts of a red dye of Formula (12);

wherein all parts are by weight and the sum of the parts (a), (b) and(c)=100:

The dye of Formula (9) may be prepared using conventional methods forthe preparation of azo dyes. For example a suitable method comprises:

(1) diazotising the aniline disulphonic acid of the formula:

(2) diazotising 2-amino-4-nitrobenzenesulphonic acid;

(3) coupling the product of stage (2) with8-amino-1-naphthol-3,6-disulphonic acid under mildly alkalineconditions;

(4) coupling the product of stage (3) with the product of stage (1)under acidic conditions;

(5) reducing the nitro group on the product of stage (4), for example byhydrogenation over a palladium catalyst;

(6) condensing the product of stage (5) with the triazine compound ofthe formula:

and

(7) condensing the product of stage (5) with a compound of the formulaNHR²³R²⁴

wherein X, R²³ and R²⁴ are as hereinbefore defined.

A further preferred magenta colorant suitable for use in the first setof inks is a dye of the Formula (13) or salt thereof:

wherein:

Q is halogen or a group of the formula —NR²⁵R²⁶ or —OR²⁵, wherein

R²⁵ is H or optionally substituted alkyl;

R²⁶ is H, optionally substituted aryl or optionally substituted alkyl;and

X is as hereinbefore defined.

It is preferred that R²⁵ is H or optionally substituted C₁₋₄-alkyl, morepreferably H or C₁₋₄-alkyl and especially H or methyl.

Preferably R²⁶ is H, optionally substituted phenyl or optionallysubstituted C₁₋₆-alkyl, more preferably H, C₁₋₆-alkyl or phenylsubstituted by C₁₋₄-alkyl, —COOH or —SO₃H, especially C₁₋₆-alkyl andphenyl substituted by methyl, ethyl or —SO₃H and more especially phenylsubstituted with —SO₃H and —COOH.

When Q is halogen it is preferably chloro.

Preferably Q is a group of the formula —NR²⁵R²⁶, more preferably —NHR²⁶.

The dyes of Formula (13) may be prepared using methods analogous tothose described in the art for other azo dyes. For example a suitablemethod is described in GB 899,376.

Although Formulae (1) to (13) show the dyes in their free acid form, itis intended that salts of the dyes are included within the scope of thepresent invention. Thus the inks may contain dyes in their free acidand/or salt forms.

In view of the foregoing preferences for the colorants for the first setof inks, in a particularly preferred embodiment, the first set of inkscomprises an ink containing a dye of Formula (5), an ink containing adye of Formula (6) an ink containing a dye of Formula (7) and an inkcontaining a dye of Formula (8) or a dye of Formula (9); and the secondset of inks comprises an ink containing a dye of Formula (1), an inkcontaining a dye of Formula (2) an ink containing a dye of Formula (3)and an ink containing a dye of Formula (4).

The labile group or atom represented by X in the dyes of Formulae (1) to(9) is a group or atom which is bound directly to the triazine nucleusand which is readily displaced therefrom in mildly alkaline conditions.Preferred labile groups include for example, a sulphonic acid group; athiocyano group; a quaternary ammonium group, for example a trialkylammonium group or an optionally substituted pyridinium group, forexample 3- or 4-caboxypyridinium; —OSO₃H; or CH₃COO—.

Preferred labile atoms include halogens, more preferably F, Cl or Br andespecially Cl.

When the substituents on the dyes of Formulae (1) to (13) are optionallysubstituted, preferred substituents are selected from —OH, —SO₃H, —COOH,—CN, —NO₂, —PO₃H₂, halogen, especially Cl or Br, C₁₋₄-alkyl andC₁₋₄-alkoxy.

It is preferred that the colorants/dyes present in the inks are purifiedprior to incorporation into the ink by removing substantially all of theinorganic salts and other by products which may be present in thecolorant/dye. Suitable purification processes include reverse osmosisand/or ultrafiltration.

The inks used in the first and second set of inks of the presentinvention comprise the relevant colorant or dye and a medium. The inksmay comprise a mixture of two or more different colorants or dyes, orsalts thereof, to provide an ink composition of the desired colour foruse as an ink of the first or second set of inks of the presentinvention.

The medium for the ink compositions may be a liquid or a low meltingpoint solid. Liquid media may be aqueous or solvent-based.

It is preferred that when dyes are used in the inks they are dissolvedcompletely in the aqueous or solvent medium to form a solution.

Preferred inks are those comprising a dye, preferably a dye of theFormula (1) to (9) as hereinbefore defined and an aqueous medium.

The inks used in the method of the present invention preferably containfrom 0.5% to 20%, more preferably from 0.5% to 15%, and especially from2% to 12% by weight of the dye/colorant based on the total weight of theink It is preferred that where the colorant is a dye, it has asolubility of around 10% or more to allow the preparation ofconcentrates which may be used to prepare more dilute inks and tominimise the chance of precipitation of the dye if evaporation of theliquid medium occurs during use of the ink.

Where the colorant is a dye its solubility can be enhanced by convertingthe sodium salt, in which form it is usually synthesised, eitherpartially or wholly, into the lithium or ammonium salt Purification ofthe dye can be conveniently accomplished by use of membrane separationprocesses to separate unwanted by-products and inorganic materials fromthe solution or dispersion of the dye, followed by partial or completeexchange of the counter ion.

Where the liquid medium is aqueous based it is preferably water or amixture of water and one or more water-soluble organic solvent. Theweight ratio of water to organic solvent(s) is preferably from 99:1 to1:99, more preferably from 95:1 to 50:50 and especially from 90:10 to60:40.

The water-soluble organic solvent is preferably selected fromC₁₋₄-alkanols such as methanol, ethanol, n-propanol, isopropanol,n-butanol, sec-butanol, tert-butanol or isobutanol; amides such asdimethylformamide or dimethylacetamide; ketones or ketone-alcohols suchas acetone or diacetone alcohol; ethers such as tetrahydrofuran ordioxane; oligo- or poly-alkylene glycols such as diethylene glycols,triethylene glycol, polyethylene glycol or polypropylene glycol;alkenyleneglycols or thioglycols containing a C₂-C₆-alkylene group suchas ethylene glycol, propylene glycol, butylene glycol, pentylene glycolor hexylene glycol, thioglycol and thiodiglycol; polyols such asglycerol or 1,2,6-hexanetriol; C₁₋₄-alkyl-ethers or polyhdric alcoholssuch as 2-methoxyethanol, 2-2-(2-methoxyethoxy)ethanol,2-(2-ethoxyethoxy)-ethanol, 2-[2-(2-methoxyethoxy)ethoxy]ethanol,2-[2-(2-ethoxyethoxy)-ethoxy]-ethanol; heterocyclic ketones, such as2-pyrrolidone and N-methyl-2-pyrrolidone; or mixtures containing two ormore of the aforementioned water-soluble organic solvents for examplethiodiglycol and a second glycol or diethylene glycol and 2-pyrrolidone.

Preferred water-soluble organic solvents are 2-pyrrolidone;N-methylpyrrolidone; alkylene glycols and oligo-alkylene glycols, suchas ethylene glycol, diethylene glycol, triethylene glycol; and loweralkyl ethers of polyhydric alcohols such as2-methoxy-2-ethoxy-2-ethoxy-ethanol; polyethylene glycols with amolecular weight of up to 500; and thioglycols such as thiodiglycols. Apreferred specific solvent mixture is a binary or ternary mixture ofwater and diethylene glycol and/or, 2-pyrrolidone or N-methylpyrrolidonein weight ratios 75-95:25-5 and 60-98:1-20:1-20 respectively. Anespecially preferred specific solvent mixture is a binary or tertiarymixture of water and thiodiglycol and/or 2-pyrrolidone orN-methylpyrrolidone in weight ratios 75-98:25-2 and 60-90:5-20:5-20respectively.

Examples of suitable aqueous ink media are given in U.S. Pat. Nos.4,963,189, 4,703,113, 4,626,284, EP 4,251,50A and U.S. Pat. No.5,207,824.

When aqueous inks are used in the present invention, they preferablyalso contain a humectant to inhibit evaporation of water and apreservative to inhibit the growth of fungi, bacteria and/or algae inthe solution. Examples of suitable humectants are, propan-1,2-diol,butan-1,2-diol, butan-2,3-diol and butan-1,3-diol. However, the presenceof small amounts, up to about 10%, preferably not more than 5%, intotal, of polyols having two or more primary hydroxy and/or primaryalcohols is acceptable, although the ink is preferably free from suchcompounds

Where the liquid medium is solvent based the solvent is preferablyselected from ketones, alkanols, aliphatic hydrocarbons, esters, ethers,amides or mixtures thereof. Where an aliphatic hydrocarbon is used asthe solvent a polar solvent such as an alcohol, ester, ether or amide ispreferably added. Preferred solvents include ketones, especially methylethyl ketone and alkanols especially ethanol and n-propanol.

Solvent based ink compositions are used where fast drying times arerequired and particularly when printing onto hydrophobic substrates suchas plastics, metal or glass.

Where the medium for an ink composition is a low melting point solid themelting point of the solid is preferably in the range from 60° C. to125° C. Suitable low melting point solids include long chain fatty acidsor alcohols, preferably those with C₁₈₋₂₄ chains, or sulphonamides. Thedye or colorant may be dissolved in the low melting point solid or maybe finely dispersed in it.

The inks may optionally contain other components conventionally used ininks for ink jet printing. For example, viscosity and surface tensionmodifiers, corrosion inhibitors, kogation reducing additives,surfactants and anti-cockle agents, for example those disclosed in U.S.Pat. No. 5,207,824, column 3, line 13 to column 4, line 21, which isincluded herein by reference thereto.

If desired, the inks may be buffered to a pH of from 5 to 8, morepreferably from 6 to 7, with a suitable buffer such as the sodium saltof metanillic acid or an alkali metal phosphate.

Where the ink jet printing technique involves the charging andelectrically-controlled deflection of drops, for example in a continuousink jet printer, the inks preferably also contain a conducting materialsuch as an ionised salt to enhance and stabilise the charge applied tothe drops. Suitable salts for this purpose are alkali metal salts ofmineral acids.

In view of the foregoing preferences, a particularly preferred inkcomposition is an aqueous ink comprising the components:

(a) 0.5 to 20 parts of the relevant dye;

(b) 50 to 98 parts water; and

(c) 2 to 50 parts water soluble organic solvent;

wherein all parts are parts by weight and the parts (a)+(b)+(c)=100. Inaddition to the components (a), (b) and (c), the ink may also containfurther components as hereinbefore mentioned.

The ink jet printer used for the application of the inks to thesubstrate forms each ink into small droplets by ejection from areservoir through a small orifice (the ink jet nozzle) so that the inkdroplets are directed at the substrate during relative movement betweenthe substrate and the reservoir. This process is commonly referred to asink jet printing. The ink may be applied to the substrate using a“continuous” or a “drop on demand” printer, both of which are well knownin the art. Continuous ink jet printers produce a stream of ink from theink jet nozzle which is formed into droplets and directed to thesubstrate via a suitable control means. Drop on demand printers ejectindividual droplets of ink from the ink jet nozzle in response to acontrol signal. Preferred drop on demand ink jet printers for use in thepresent invention are piezoelectric and thermal ink jet printers. Inthermal ink jet printing, programmed pulses of heat are applied to theink in the reservoir by means of a resistor adjacent to the ink jetnozzle. In piezo-electric printers ink droplets are ejected from the inkjet nozzle using a piezoelectric transducer. The transducer oscillatesin response to an electrical control signal, thereby creating a pressurewave in the reservoir adjacent to the ink jet nozzle which ejectsdroplets of ink from the nozzle.

Ink jet printers suitable for use in the present invention apply atleast one ink from the first set of inks and at least one ink from thesecond set of inks, wherein the first and second sets of inks are ashereinbefore defined.

Preferably the ink jet printer applies a first set of inks consisting ofblack, cyan, magenta and yellow inks and from one to four, preferablyfrom two to four and especially four of the hereinbefore defined inks ofthe second set of inks.

Ink jet printers suitable for use in the present invention require ameans to access each of the inks comprising the first and second sets ofinks, for example from separate ink tanks containing each ink.

Preferably the inks comprising the first and second set of inks arecontained in an ink cartridge suitable for use in an ink jet printer.The ink cartridge preferably comprises a container in which are held thefirst and second set of inks. Preferably the ink jet printer containsthe ink cartridge, for example within a suitable housing in the printer.

It is preferred that the printer has a separate channel to direct eachink colour in the first and second set of inks to a nozzle, or array ofnozzles, dedicated to that ink colour. The separate ink channels foreach ink colour avoids cross contamination of inks in the ink jet headwhich could result in an undesirable colour on the printed substrate.Accordingly, preferred ink jet printers have from 5 to 8, morepreferably from 6 to 8 and especially 8 ink channels. An example of anink jet printer suitable for use in the present invention is describedin EP 616 893 A2.

The substrate used in the ink-jet method of the present invention may bepaper, plastics, textile, metal, ceramic or glass and is preferablypaper, plastic or a textile material, especially a natural,semi-synthetic or synthetic material.

Examples of natural textile materials include wool, silk, hair andcellulosic materials, particularly cotton, jute, hemp, flax and linen.

Examples of synthetic and semi-synthetic materials include polyamides,polyesters, polyacrylonitriles and polyurethanes.

Preferred substrates include overhead projector slides paper and textilematerials. Preferred papers include plain and treated papers. Preferredtextile materials are cellulosic materials such as cotton. Especiallypreferred substrates are treated papers suitable for high resolution“photo-realistic” image printing and cellulosic textile materials.

According to a second aspect of the present invention there is provideda set of ink jet printing inks comprising a first and second set of inkswherein:

(a) the first set of inks consists of a yellow ink, a magenta ink, acyan ink and optionally a black ink; and

(b) the second set of inks comprises one or more inks selected from:

an ink containing a dye of Formula (1) or salt thereof;

an ink containing a dye of the Formula (2) or a salt thereof;

an ink containing a dye of Formula (3) or a salt thereof; and

an ink containing a dye of Formula (4) or a salt thereof;

wherein the dyes of Formulae (1), (2), (3) and (4) are as hereinbeforedefined in the first aspect of the present invention.

Preferred inks in the set according to the second aspect of the presentinvention are as defined in the first aspect of the present invention.

Accordingly a preferred set of ink jet printing inks comprises:

(a) a first set of inks consisting of:

a cyan ink containing a dye of the Formula (5);

a yellow ink containing a dye of Formula (6);

a magenta ink containing a dye of the Formula (7) or Formula (13); and

a black ink containing a dye of the Formula (8) or Formula (9); and

(b) a second set of inks comprising from one to four, preferably fromtwo to four and especially four inks selected from:

an ink containing a dye of Formula (1);

an ink containing a dye of Formula (2);

an ink containing a dye of Formula (3);and

an ink containing a dye of Formula (4).

According to a third aspect of the present invention there is provided apaper or an overhead projector slide, a metal, glass or ceramicsubstrate or textile material coloured by means of the method accordingto the first aspect of the present invention.

According to a fourth aspect of the present invention there is provideda process for the coloration of a textile material using ink-jetprinting which comprises the steps:

i) applying to the textile material by ink-jet printing the inks fromthe first and second sets of ink in accordance with the method of thefirst aspect of the present invention; and

ii) heating the textile material at a temperature from 50° C. to 250° C.to fix the dyes and colorants on the material.

The process for coloration of a textile material by ink-jet printingpreferably comprises a pre-treatment of the textile material with anaqueous pretreatment composition comprising a water-soluble base, ahydrotropic agent and a thickening agent followed by removing water fromthe pre-treated textile material to give a dry pre-treated textilematerial which is subjected to ink-jet printing in step i) above.

The pre-treatment composition preferably comprises a solution of thebase and the hydrotropic agent in water containing the thickening agent.

The base is preferably an inorganic alkaline base, especially a salt ofan alkali metal with a weak acid such as an alkali metal carbonate,bicarbonate or silicate or an alkali metal hydroxide. The amount of basemay be varied within wide limits provided sufficient base is retained onthe textile material after pre-treatment to promote the dyeing of thepre-treated textile material. Where the base is sodium bicarbonate it isconvenient to use a concentration of from 1% to 5% by weight based onthe total weight of the composition.

The hydrotropic agent is present to provide sufficient water to promotethe fixation reaction between the dye and the textile material duringthe heat treatment, in step (ii) above, and any suitable hydrotropicagent may be employed. Preferred hydrotropic agents are urea, thioureaand dicyandiamide. The amount of hydrotropic agent depends to someextent on the type of heat treatment. If steam is used for the heattreatment generally less hydrotropic agent is required than if the heattreatment is dry, because the steam provides a humid environment. Theamount of hydrotropic agent required is generally from 2.5% to 50% byweight of the total composition with from 2.5% to 10% being moresuitable for a steam heat treatment and from 20% to 40% being moresuitable for a dry heat treatment.

The thickening agent may be any thickening agent suitable for use in thepreparation of print pastes for the conventional printing of cellulosereactive dyes. Suitable thickening agents include alginates, especiallysodium alginate, xantham gums, monogalactam thickeners and cellulosicthickeners. The amount of the thickening agent can vary within widelimits depending on the relationship between concentration andviscosity. However, sufficient agent is preferred to give a viscosityfrom 10 to 1000 mPa.s, preferably from 10 to 100 mPa.s, (measured on aBrookfield RVF Viscometer). For an alginate thickener this range can beprovided by using from 10% to 20% by weight based on the total weight ofthe pretreatment composition.

The remainder of the pre-treatment composition is preferably water, butother ingredients may be added to aid fixation of the dye to the textilematerial or to enhance the clarity of print by inhibiting the diffusion(migration) of dye from coloured areas to non-coloured areas beforefixation.

Examples of fixation enhancing agents include cationic polymers andquaternary ammonium compounds. Suitable cationic polymers include forexample, a 50% aqueous solution of a dicyanamide/phenolformaldehydelammonium chloride condensate e.g. MATEXIL FC-PN (availablefrom ICI), which have a strong affinity for the textile material and thedye and thus increase the fixation of the dye on the textile material.Suitable quaternary ammonium compounds include for example thosedescribed in our EP 534 660 A1, incorporated herein by referencethereto, such as distearyl dimethylammonium chloride.

Examples of anti-migration agents are low molecular weight acrylicresins, e.g. polyacrylates, such as poly(acrylic acid) and poly(vinylacrylate).

In the pre-treatment stage of the present process the pre-treatmentcomposition is preferably evenly applied to the textile material. Wherea deeply penetrated print or a deep shade is required the pretreatmentcomposition is preferably applied by a padding or similar process sothat it is evenly distributed throughout the material. However, whereonly a superficial print is required the pre-treatment composition canbe applied to the surface of the textile material by a printingprocedure, such as screen or roller printing, ink jet printing or barapplication.

In the pre-treatment stage of the present process, water may be removedfrom the pre-treated textile material by any suitable drying proceduresuch as by exposure to hot air or direct heating, e.g. by infra-redradiation, or micro-wave radiation, preferably so that the temperatureof the material does not exceed 100° C.

The application of the ink composition to the textile material, stage(i) of the present process, is as hereinbefore defined for thecoloration method of the first aspect of the present invention. It ispreferred that each ink of the first set of inks contains a reactivedye.

After application of the ink, it is generally desirable to remove waterfrom the printed textile material at relatively low temperatures (<100°C.) prior to the heat applied to fix the dye on the textile material asthis has been found to minimise the diffusion of the dye from printed tonon-printed regions. As with the pretreated textile material removal ofwater is preferably by heat, such as by exposure to hot air or toinfra-red or micro-wave radiation.

In stage (ii) of the present process, the printed textile material issubmitted to a short heat treatment, preferably after removal of waterby low-temperature drying, at a temperature from 100° C. to 200° C. byexposure to dry or steam heat for a period of up to 20 minutes. If asteam (wet) heat treatment is used, the printed material is preferablymaintained at 100-105° C. for from 5 to 15 minutes whereas if a dry heattreatment is employed the printed material is preferably maintained at140-160° C. for from 2 to 8 minutes.

After allowing the textile material to cool, unfixed dye and otheringredients of the pretreatment and dye compositions may be removed fromthe textile material by a washing sequence, involving a series of hotand cold washes in water and aqueous detergent solutions before thetextile material is dried.

According to a fifth aspect of the present invention there are providedtextile materials, especially cellulosic textile materials, coloured bymeans of the process according to the fourth aspect of presentinvention.

According to a sixth aspect of the present invention there is provided aphotorealistic print prepared using the coloration method according tothe first aspect of the present invention.

A photorealistic print is a high resolution print which reproduces animage from digital data corresponding to that image. The photorealisticprints prepared in accordance with the present invention exhibitexcellent colour yield and a wide colour gamut compared with imagesformed by conventional CMYK ink jet printers.

Examples of systems which prepare images in digitised form includedigital cameras, images stored on a CD ROM system, images that have beendigitised using an optical scanning device and computer graphicsprograms such as CAD/CAM systems.

The digital data corresponding to the image is used by a computer tocontrol the discharge of inks selected from the first and second sets ofink from an ink jet printer in accordance with the coloration method ofthe first aspect of the present invention, thereby providing aphotorealistic print corresponding to the digitised image on asubstrate.

The substrate used in the preparation of photorealistic prints may beany of the hereinbefore mentioned substrates. However, preferredsubstrates are paper, more preferably coated paper. Examples of paperand coated paper substrates suitable for use in the preparation ofphotorealistic prints include Hewlett Packard coated papers such as HP516347, HP Premium Coated Paper and HP Photopaper, Stylus Pro 720 dpiCoated Paper, Epson Photo Quality Glossy Film (available from SeikoEpson Corp.), Epson Photo Quality Glossy Paper (available from SeikoEpson Corp.) Canon HR 101 High Resolution Paper (available from Canon),Canon GP 201 Glossy Paper (available from Canon), and Canon HG 101 HighGloss Film (available from Canon).

The present invention is further illustrated by the following examplesand by reference to FIG. 1.

Ink Compositions Suitable for use in the Present Invention

EXAMPLE 1

Golden yellow ink compositions containing a mixture of dyes of Formula(1) wherein:

R¹ is —NH₂;

X is Cl; and

A is a mixture of N-methyl-3sulphoanilino and N-methyl4-sulphoanilino;were made according to each of the formulations shown in Tables I and 11wherein figures denote parts by weight for each component. The columnmarked “dye content” in Tables (I) and (II) refers to the parts byweight of the dye of Formula (1).

Each ink was prepared by first purifying the dye mixture of Formula (1)by desalination using reverse osmosis and ultrafiltration. The purifieddye was then added to a mixture of the other components comprising thatink formulation and was stirred to form a solution. The ink was thenfiltered using a 0.45 micron filter to remove any particulate matterthat may have been present in the ink.

The following abbreviations are used:

PG=propylene glycol

DEG=diethylene glycol

NMP=N-methyl pyrollidone

DMK=dimethylketone

IPA=isopropanol

MEOH-methanol

2P=2-pyrollidone

MIBK=methylisobutyl ketone

P12=propane-1,2-diol

BDL butane=2,3-diol

CET=cetyl ammonium bromide

PHO=Na₂HPO₄ and

TBT=tertiary butanol

TDG=thiodiglycol

TABLE I Dye Ink No. Content Water PG DEG NMP DMK NaOH Na Stearate IPAMEOH 2P MIBK  1 2.0 80 5 6 4 5  2 3.0 90 5 5 0.2  3 10.0 85 5 2 2 5 1  42.1 91 8 1  5 3.1 86 5 0.2 4 5  6 1.1 81 9 0.5 0.5 9  7 2.5 60 4 15  3 36 10  5 4  8 5 65 20  10   9 2.4 75 5 4 5 6 5 10 4.1 80 3 5 2 10  0.3 113.2 65 5 4 6 5 4 6 5 12 5.1 96 4 13 10.8 90 5 5 14 10.0 80 2 6 2 5 1 415 1.8 80 5 15  16 2.6 84 11  5 17 3.3 80 2 10  2 6 18 12.0 90 7 0.3 319 5.4 69 2 20  2 1 3 3 20 6.0 91 4 5

TABLE II Dye Ink No. Content Water PG DEG NMP CET TBT TDG BDL PHO 2P P1221 3.0 80 15 0.2 5 22 9.0 90 5 1.2 5 23 1.5 85  5 5 0.15 5.0 0.2 24 2.590 6 4 0.12 25 3.1 82  4 8 0.3 6 26 0.9 85 10  5 0.2 27 8.0 90 5 5 0.328 5.0 70 10  4 1 4 11  29 2.2 75  4 10  3 2 6 30 10.0 91 6 3 31 9.0 769 7 3.0 0.95 5 32 5.0 78  5 11  6 33 5.4 86 7 7 34 2.1 70  5 5 5 0.1 0.20.1 5 0.1 5 35 2.0 90 10  36 2 88 10 37 5 78 5 12 5 38 8 70  2 8 15 5 3910 80 8 12  40 10 80 10 

EXAMPLE 2

Orange inks according to each of the formulations shown in Tables (I)and (II) were prepared using a dye of Formula (2) wherein:

R⁴ is —CH₃;

B is —NH₂; and

X is Cl.

The inks were prepared by first purifying the dye and mixing thecomponents of each formulation as in Example 1.

EXAMPLE 3

Red inks according to each of the formulations shown in Tables (I) and(II) were prepared using a dye of Formula (3) wherein:

E is 2-methylanilino; and

X is Cl.

The inks were prepared by first purifying the dye and mixing thecomponents of each formulation as in Example 1.

EXAMPLE 4

Blue inks according to each of the formulations shown in Tables (I) and(II) were prepared using a dye of Formula (4) wherein:

each W is 2,4-disulphoanilino;

each L is —CH₂CH₂—; and

each X is Cl.

The inks were prepared by first purifying the dye and mixing thecomponents of each formulation as in Example 1.

EXAMPLE 5

Cyan inks according to each of the formulations shown in Tables (I) and(II) were prepared using a dye of Formula (5) wherein:

Z is methoxy;

X is Cl;

a=2.7 and b=1.3.

The inks were prepared by first purifying the dye and mixing thecomponents of each formulation as in Example 1.

EXAMPLE 6

Yellow inks according to each of the formulations shown in Tables (I)and (II) were prepared using a dye of Formula (6) wherein:

Y is NH₂;

R¹⁴ is ethyl;

and each X is Cl.

The inks were prepared by first purifying the dye and mixing thecomponents of each formulation as in Example 1.

EXAMPLE 7

Magenta inks according to each of the formulations shown in Tables (I)and (II) were prepared using a dye of Formula (7) wherein:

G is 4-methyl-2-sulphoanilino;

R¹⁹ and R²⁰ are methyl; and

X is Cl.

The inks were prepared by first purifying the dye and mixing thecomponents of each formulation as in Example 1.

EXAMPLE 8

Black inks according to each of the formulations shown in Tables (I) and(II) were prepared using a dye of Formula (8) which comprises a mixtureof 1:2 complexes of Cr and Co with the dye of Formula (8) wherein:

T is NH₂; and

X is Cl;

said mixture comprising 70 parts of the 1:2 Cr complex and 30 parts ofthe 1:2 Co complex with the dye of Formula (8).

The inks were prepared by first purifying the dye mixture and mixing thecomponents of each formulation as in Example 1.

EXAMPLE 9

Magenta inks according to each of the formulations shown in Tables (I)and (II) were prepared using a dye of Formula (13) wherein:

X is Cl; and

Q is 2-carboxy-4-sulphoanilino.

The inks were prepared by first purifying the dye and mixing thecomponents of each formulation as in Example 1.

EXAMPLE 10

The ink combinations shown in Table III may be applied to a papersubstrate using an ink jet printer to achieve a wide colour gamut. InTable III, the Inks A to H correspond to ink formulation number 36 shownin Table II of Examples 1 to 8 respectively (i.e. 10 parts diethyleneglycol, 88 parts water and 2 parts of the relevant dye).

TABLE III First Set of Inks Second Set of Inks Combination Ink A Ink BInk C Ink D Ink E Ink F Ink G Ink H No. (golden yellow) (orange) (red)(blue) (cyan) (yellow) (magenta) (black) 1 x x x x x x x x 2 x x x x x xx 3 x x x x x x 4 x x x x x x 5 x x x x x x x 6 x x x x x x 7 x x x x x8 x x x x 9 x x x x x 10  x x x x

EXAMPLE 11

The ink combinations shown in Table III may be applied to a textilematerial such as viscose rayon or cotton using ink formulation 40 inTable II of Examples 1 to 8 for the inks A to H respectively. Preferablythe textile is pre-treated with a composition comprising:

2.5 pts sodium bicarbonate;

15 pts of a 10% aqueous solution of sodium alginate thickening agent;

15 pts of urea;

47.5 pts of water; and

20 parts of Composition A shown in Table IV.

TABLE IV Composition A Component Parts by Weight Urea 25 DistearylDimethyl Ammonium Chloride 2.3 Isopropyl Alcohol 0.8 Castor Oil + 2.5Ethylene Oxide 2.2 Castor Oil + 4.0 Ethylene Oxide 0.36 Sodium LaurylSulphate 0.010 Methanol 0.007 Formaldehyde 0.0001 Tallow Amine + 15Ethylene Oxide 0.25 Acetic Acid (80%) 0.05 Water 69.0

The textile material should be thoroughly soaked with the pretreatmentcomposition in a padding bath and the excess liquor removed by mangling.The material should then be dried in hot air, for example at atemperature of 90 to 120° C. prior to application of the inks shown inTable III by an ink jet printer.

EXAMPLE 12

Textile Printing with a Conventional Set of Inks Containing DyesSelected From Magenta, Cyan and Yellow Only

The colour gamut which can be achieved using inks containing one or moredyes selected from magenta, yellow and cyan (i.e. a first set of inks)was measured by ink jet printing the inks shown in Table (v) onto aMercerised cotton substrate using a Hewlett Packard HP-560 ink jetprinter. After printing the cotton was steamed for 8 minutes at 102° C.and a relative humidity of 100%.

The prints were then washed as follows:

(a) a cold rinse in water at ambient temperature;

(b) a 5 minute rinse in water containing an anionic soap at 90° C.; and

(c) a final cold rinse in water at ambient temperature.

In Table (v) each ink comprises the parts by weight of each of the dyesshown dissolved in (100-no. of dye parts) parts of an ink mediumcomprising 90 parts water and 10 parts diethylene glycol.

In Table (v) the following cyan, magenta and yellow dyes were used:

The dye marked “Cyan” in Table (v) was of the structure:

The dye marked “Magenta (1)” in Table (v) was of the structure:

The dye marked “Magenta (2)” in Table (v) was of the structure:

The dye marked “Yellow” in Table (v) was of the structure:

All of the above dyes are available from Zeneca Limited.

After printing and washing the colour co-ordinates of each of the printswas measured using a CIE ANLAB at a 10° observer angle with a D65illuminant. The resulting colour co-ordinates are shown in Table (vi).

In FIG. 1 the colour gamut achieved using inks with these conventionalcyan, magenta and yellow inks is shown as the points marked x. In FIG. 1the number next to each point corresponds with the print number shown inTables (v) and (vi) above.

TABLE (V) Dye (Parts) Print No Cyan Magenta 1 Magenta 2 Yellow 1 4 2 3.50.625 3 3 1.25 4 2.5 1.875 5 2 2.5 6 1.5 3.125 7 1 3.75 8 0.5 4.37 9 0 517 5 18 4.37 0.937 19 3.75 1.875 20 3.12 2.813 21 2.5 3.75 22 1.87 4.6923 1.25 5.62 24 0.625 6.56 25 7.5 37 3.5 0.937 38 3 1.875 39 2.5 2.81240 2 3.75 41 1.5 4.687 42 1 5.625 43 0.5 6.562 44 7.5

TABLE (VI) Table (VI): Colour Space Coordinates for Prints on Cotton(First set of inks only) Colour Space Coordinates Print Number L a b c HInteg 1 57.882 29.238 −26.7 39.591 222.4 3.58 2 48.325 −9.218 −28.7630.197 252.23 4.5 3 41.266 2.262 −28.59 28.679 274.52 6.12 4 42.24 5.36−26.9 27.425 281.27 5.33 5 39.697 9.89 −25.68 27.515 291.07 6.18 638.388 15.708 −24.31 28.943 302.87 6.68 7 36.221 19.693 −23.1 30.352310.45 8.02 8 37.222 28.682 −18.16 33.949 327.66 7.95 9 39.704 52.573−4.898 52.801 354.68 12.53 17 25.725 20.455 −27.91 34.605 306.23 13.3618 42.092 44.648 12.245 46.296 15.336 11.23 19 44.08 40.872 21.10345.998 27.308 11.5 20 44.851 40.286 26.622 48.287 33.458 12.93 21 46.56238.18 32.326 50.027 40.254 14.09 22 49.763 33.989 39.258 51.928 49.11414.81 23 53.373 29.203 44.361 53.11 56.644 14.23 24 57.212 23.832 51.14656.426 65.016 14.79 25 78.356 −9.152 82.771 83.276 96.31 14.36 36 69.88216.112 77.854 79.504 78.307 14.94 37 54.814 −47.13 8.759 47.935 169.475.51 38 54.771 −50.6 21.036 54.794 157.42 7.64 39 55.107 −48.75 28.33756.384 149.83 8.54 40 57.293 −48.99 35.586 60.553 144.01 9.48 41 58.559−46.84 41.751 62.745 138.29 10.81 42 62.958 −43.12 51.078 66.842 130.1711.37 43 63.602 −41.01 56.238 69.639 126.08 14.05 44 78.361 −7.98 82.83783.22 95.502 13.96

EXAMPLE 13

Ink Jet Printing onto Cotton Using a First and Second Set of Inks

To illustrate the increase in colour gamut achieved using a first and asecond set of inks the method according to the present invention wassimulated by ink jet printing cotton substrates with each of the inksshown in Table (vii). In Table (vii) the column marked “first set”refers to the same cyan, magenta and yellow dyes used in Example 12. Thecolumn marked “second set” refers to dyes of the hereinbefore definedFormula (1) to (4).

Each ink in Table (vii) comprised the number of parts of the relevantdye(s) dissolved in a medium comprising a mixture of 10 parts diethyleneglycol and 90 parts water. For example print 16 in Table (vii) comprised3.75 parts of magenta (2), 2 parts of dye (1) (blue) and 94.25 parts ofthe ink medium (90:10 water: diethylene glycol).

Dye (1) was a blue dye of the hereinbefore defined Formula (5) with thestructure:

Dye (2) was a red dye of the hereinbefore defined Formula (3) with thestructure:

Dye (3) was an orange dye of the hereinbefore defined Formula (2) withthe structure:

Dye (4) was a golden yellow dye of the hereinbefore defined Formula (1)with the structure:

(As an approximately 1:1 mixture of isomers)

The colour space coordinates obtained from the cotton printed with theseinks is shown in Table (viii).

The colour gamut obtained from the inks containing the cyan, magenta andyellow dyes together with dyes (1) to (4) is shown by the points marked. The number next to each data point is the print number shown inTables (vii) and (viii).

FIG. 1 clearly shows the dramatic increase in the colour gamut obtainedwhen a first and second set of inks are used compared with ink jetprinting using conventional cyan, magenta and red inks in Example 12.

As mentioned above Example 13 is a simulation of the method according tothe present invention. When using the method according to this inventionthe inks jet printer would have, for example, eight ink channels; fourcontaining the cyan magenta, yellow and optional black inks of the firstset and four channels for the second set of inks containing dyes (1),(2), (3) and (4). To achieve a particular colour at a point on thesubstrate the printer control system applies the required mixture ofinks from the first and second set of ink to that point.

TABLE VII Dye Parts First Set Second Set Print Magenta Dye Dye No. CyanMagenta (1) (2) Yellow Dye (1) (2) Dye (3) (4)  1 4  2 3.5 0.625  3 31.25  4 2.5 1.875  5 2 2.5  6 1.5 3.125  7 1 3.75  8 0.5 4.37  9 0 10 31 11 2 2 12 1 3 13 4 14 1.25 3 15 2.5 2 16 3.75 2 17 5 18 4.37 0.937 193.75 1.875 20 3.12 2.813 21 2.5 3.75 22 1.87 4.69 23 1.25 5.62 24 0.6256.56 25 7.5 26 3 1 27 1 3 1 28 5 3 1 29 3 5 3 30 1 3 5 31 1 3 32 32 3334 35 2.5 36 5 37 3.5 0.937 38 3 1.875 39 2.5 2.812 40 2 3.75 41 1.54.687 42 1 5.625 43 0.5 6.562 44 7.5

TABLE (viii) Colour Space Coordinates for Prints on Cotton Using a Firstand Second Set of Inks Colour Space Coordinates Print No. L a b c HInteg 1 57.882 29.238 −26.7 39.591 222.4 3.58 10 44.709 −13.2 −32.535.08 247.9 7.33 11 40.538 −6.838 −34.88 35.541 258.91 9.12 12 37.622−3.574 −35.01 35.187 264.17 10.78 13 33.554 0.667 −35.82 35.823 271.0714.42 14 29.633 10.906 −33.69 35.406 287.94 15.08 15 28.753 17.181 −3034.572 299.8 14.59 16 25.725 20.455 −27.91 34.605 306.23 18.78 17 25.72520.455 −27.91 34.605 306.23 13.36 18 42.092 44.648 12.245 46.296 15.33611.23 26 42.217 56.479 −0.063 56.479 359.94 12 27 43.041 58.035 6.45958.394 6.351 13.53 28 42.576 59.592 13.068 61.008 12.368 17.78 29 45.17557.693 22.789 62.034 21.554 15.66 30 49.756 54.313 43.49 69.579 38.68519.03 31 54.919 51.232 61.285 79.878 50.106 26.06 32 55.654 48.48763.968 80.267 52.838 25.07 37 54.814 −47.13 8.759 47.935 169.47 5.51 3854.771 −50.6 21.036 54.794 157.42 7.64 39 55.107 −48.75 28.337 56.384149.83 8.54 40 57.293 −48.99 35.586 60.553 144.01 9.48 41 58.559 −46.8441.751 62.745 138.29 10.81 42 62.958 −43.12 51.078 66.842 130.17 11.3743 63.602 −41.01 56.238 69.639 126.08 14.05 44 78.361 −7.98 82.837 83.2295.502 13.96

What is claimed is:
 1. A method for the coloration of a substratecomprising ink jet printing a first and second set of inks onto thesubstrate wherein: (a) the first set of inks comprises one or more inkseach of which independently contains a colorant selected from yellow,magenta, cyan and optionally black; and (b) the second set of inkscomprises one or more inks each of which independently contains a dyeselected from: a yellow dye of Formula (1) or salt thereof:

wherein: X is a labile group or atom; R¹ is alkyl or —NH₂; A is —NR²R³,—OR² or halogen; R² is H or optionally substituted alkyl; and R³ isoptionally substituted phenyl; an orange dye of Formula (2) or saltthereof:

wherein: R⁴ is H or optionally substituted alkyl; X is as hereinbeforedefined; B is —NR⁵R⁶, —OR⁵ or halogen; and R⁵ and R⁶ independently are Hor optionally substituted alkyl; a red dye of Formula (3) or saltthereof:

wherein: X is as hereinbefore defined; E is —NR⁷R⁸, —OR⁷ or halogen;each R⁷ is independently H or alkyl; and R⁸ is optionally substitutedaryl; and a blue dye of Formula (4) or salt thereof:

wherein: each X independently is as hereinbefore defined; each Lindependently is an optionally substituted alkylene group; each Windependently is halogen or a group of the formula —OR⁹ or —NR¹⁰R¹¹; R⁹is H or alkyl; R¹⁰ is H or optionally substituted alkyl; and R¹¹ is anoptionally substituted aryl group.
 2. A method according to claim 1wherein the first set of inks comprises an ink containing a yellowcolorant, an ink containing a magenta colorant and an ink containing acyan colorant.
 3. A method according to claim 1 wherein the first set ofinks comprises an ink containing a yellow colorant, an ink containing amagenta colorant, an ink containing a cyan colorant and an inkcontaining a black colorant.
 4. A method according to claim 1 whereinthe second set of inks comprises an ink containing a dye of Formula (1),an ink containing a dye of Formula (2), an ink containing a dye ofFormula (3) and an ink containing a dye of Formula (4), wherein formulae(1) to (4) are as defined in claim
 1. 5. A method according to claim 1wherein: (a) the first set of inks comprises an ink containing a yellowcolorant, an ink containing a magenta colorant, an ink containing a cyancolorant and an ink containing a black colorant; and (b) the second setof inks comprises an ink containing a dye of Formula (1), an inkcontaining a dye of Formula (2), an ink containing a dye of Formula (3)and an ink containing a dye of Formula (4), wherein formulae (1) to (4)are as defined in claim
 1. 6. A method according to claim 1 wherein thecolorant in each of the inks in the first set of inks is a reactive dye.7. A method according to claim 6 wherein the reactive dye contains ahalotriazine and/or a vinyl sulphone fibre-reactive group.
 8. A methodaccording to claim 1 wherein the cyan colorant in the first set of inksis a dye of the Formula (5) or salt thereof:

wherein: Pc is a phthalocyanine nucleus; Z is —NR¹²R¹³, —OR¹³ orhalogen; R¹² is H or optionally substituted alkyl; R¹³ is H, optionallysubstituted alkyl or optionally substituted aryl; X is a labile atom orgroup; a is 1 to 3; b is 1 to 3; and (a+b)=4.
 9. A method according toclaim 1 wherein the yellow colorant in the first set of inks is a dye ofFormula (6) or salt thereof:

wherein: Y is halogen or a group of the formula —NR¹⁵R¹⁶ or —OR¹⁶; R¹⁵is H or optionally substituted C₁₋₄-alkyl; R¹⁵ is H optionallysubstituted alkyl or aryl; R¹⁴ is H, optionally substituted alkyl oraryl; and each X independently is a labile atom or group.
 10. A methodaccording to claim 1 wherein the magenta colorant present in the firstset of inks is a dye of Formula (7) or salt thereof:

wherein: G is halogen or a group of the formula —NR¹⁷R¹⁸ or —OR¹⁷; R¹⁷is H or optionally substituted alkyl; R¹⁸ is H, optionally substitutedaryl or optionally substituted alkyl; R¹⁹ and R²⁰ are each independentlyC₁₋₄-alkyl; and X is a labile atom or group.
 11. A method according toclaim 1 wherein the black colorant present in the first set of inks is a1:2 Chromium (III) or Cobalt (III) complex, or mixture thereof, of theFormula (8) or salt thereof:

wherein: T is halogen or a group of the formula —NR²¹R²² or —OR²¹; R²¹is H or optionally substituted alkyl or optionally substituted aryl; R²²is H or optionally substituted alkyl; M is Cr or Co; and X is a labileatom or group.
 12. A method according to claim 1 wherein the blackcolorant in the first set of inks is a dye of Formula (9) or a saltthereof:

wherein: X is a labile atom or group; and R²³ and R²⁴ are eachindependently H or optionally substituted alkyl.
 13. A method accordingto claim 12 wherein the black colorant comprises: (a) from 50 to 95parts of the dye of the Formula (9); (b) from 5 to 20 parts of a yellowdye; and (c) from 10 to 30 parts of a red dye; wherein all parts are byweight and the sum of the parts (a), (b) and (c)=100.
 14. A methodaccording to claim 1 wherein the magenta colorant in the first set ofinks comprises a dye of the Formula (13) or a salt thereof:

wherein: Q is halogen or a group of the formula —NR²⁵R²⁶ or —OR²⁵; R²⁵is H or optionally substituted alkyl; R²⁶ is H, optionally substitutedaryl or optionally substituted alkyl; and X is a labile atom or group.15. A method according to claim 5 wherein the cyan colorant is asdefined in claim 8, the yellow colorant is as defined in claim 9, themagenta colorant is as defined in claim 10, or claim 14 and the blackcolorant is as defined in claim 11 or claim
 12. 16. A method accordingto claim 1 wherein each ink comprises a liquid medium.
 17. A methodaccording to claim 16 wherein the liquid medium comprises water and oneor more organic solvents in a weight ratio of from 99:1 to 1:99.
 18. Amethod according to claim 17 wherein the ink comprises the components:(a) 0.5 to 20 parts of the relevant dye; (b) 50 to 98 parts water; and(c) 2 to 50 parts water-soluble organic solvent; wherein all parts areparts by weight and the parts (a)+(b)+(c)=100.
 19. A method according toclaim 1 wherein the substrate is a textile.
 20. A set of ink jetprinting inks comprising a first and second set of inks wherein: (a) thefirst set of inks comprises a yellow ink, a magenta ink, a cyan ink andoptionally a black ink; and (b) the second set of inks comprises one ormore inks selected from: an ink containing a dye of Formula (1) or saltthereof; an ink containing a dye of the Formula (2) or a salt thereof;an ink containing a dye of Formula (3) or a salt thereof; and an inkcontaining a dye of Formula (4) or a salt thereof; wherein the dyes ofFormulae (1), (2), (3) and (4) are as defined in claim
 1. 21. A set ofink jet printing inks according to claim 20 comprising: (a) a first setof inks comprising: a cyan ink containing a dye of the Formula (5) asdefined in claim 8; a yellow ink containing a dye of Formula (6) asdefined in claim 9; a magenta ink containing a dye of the Formula (7) asdefined in claim 10 or a dye of the Formula (13) as defined in claim 14;and and a black ink containing a dye of the Formula (8) as defined inclaim 11 or a dye of the Formula (9) as defined in claim 12; and (b) asecond set of inks comprising from one to four inks selected from: anink containing a dye of Formula (1); an ink containing a dye of Formula(2); an ink containing a dye of Formula (3); and an ink containing a dyeof Formula (4).
 22. A process for the coloration of a textile materialcomprising: (i) applying to the textile material by ink-jet printing theinks from the first and second sets of ink in accordance with the methodof claim 1; and (ii) heating the textile at a temperature of from 50° C.to 250° C. to fix the dye on the textile.
 23. A process according toclaim 22 wherein the textile is a cellulosic material.
 24. A textilecoloured by means of a process according to claim
 22. 25. A processaccording to claim 1 wherein the substrate is paper.
 26. A papercoloured by a process according to claim
 25. 27. A photorealistic printprepared using the coloration method according to of claim
 1. 28. An inkjet printer, characterised in that the printer contains at least one inkfrom the first set of inks and at least one ink from the second set ofinks, wherein the first and second sets of inks are as defined inclaim
 1. 29. An ink jet printer according to claim 28, characterised inthat it has a separate channel to direct each ink colour in the firstand second set of inks to a nozzle or array of nozzles dedicated to thatcolour.
 30. An ink jet printer according to claim 29 which has from 5 to8 channels.
 31. An ink cartridge suitable for use in an ink jet printerwhich comprises a container in which are held the first and second setof ink, wherein the first and second set of ink are as defined in claim20.
 32. An ink jet printer according to claim 28 containing an inkcartridge according to claim 31.